The mobile phase consisted on a mixture of eluent A (formic acid 0.1%) and eluent B (methanol). The analysis was performed using the following program of eluents: 0–5 min from 0 until 30% eluent B; 5–15 min, from 30 until 95% eluent B; 15–30min; from 95 until 30% eluent B. The separations were carried out with a flow rate of 0.3 mL/min.